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Homework Help: Dalton's Law question.

  1. Oct 14, 2007 #1
    1. The problem statement, all variables and given/known data

    A sample was collected into a 1.25L tank at 752 mm Hg and analyzed. The analysis showed 92% CO2, 3.6% NO, 1.2% SO2, and 4.1% H2O by mass(key word mass). what is the partial pressure exerted by each gas.

    attempt at a solution:
    I know that you need to times the percent of gas in the tank by the pressure.
    But I try this question so many times keep get me the wrong answer.
    so please show step by step solution please.
    I am have a quiz tomorrow so please teach me how to do this problem thanks.
  2. jcsd
  3. Oct 14, 2007 #2
    This might work: assume 100g total mass sample. Then 92g is CO2, 3.6 g NO etc...

    Calculate the mole of each gas with the above masses 92g CO2 = > ? mol CO2

    Add up all the moles to get total moles

    - mole fraction (mol CO2/total moles)is proportional to partial pressure/total pressure,
    - total pressure is given in the problem.
  4. Oct 14, 2007 #3
    It dosen;t seem working!
  5. Oct 15, 2007 #4
    are you sure the % values are correct? If you add up all the numbers I get 100.9%, this could make a difference in the partial pressures
  6. Oct 15, 2007 #5
    That's how it is on the book check thousand times!
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